1. Field of the Invention
The invention relates to a heat insulator that covers an exhaust pipe of an internal combustion engine. The invention especially relates to a heat insulator that covers an exhaust pipe having a bent part.
2. Description of Related Art
Conventionally, as disclosed in Japanese Patent Application Publication No. 2005-307988 (JP 2005-307988 A), a heat insulator assembled to an exhaust pipe through a sliding mechanism is known. The heat insulator disclosed in JP 2005-307988 A covers an exhaust pipe made from a straight pipe, and one end side of the heat insulator in a longitudinal direction (in a direction along an exhaust gas flow) is fixed to the exhaust pipe, and the other end side of the heat insulator is assembled to the exhaust pipe by a sliding mechanism so as to be able to move relative to the exhaust pipe. Therefore, even when high-temperature exhaust gas flows inside the exhaust pipe causing the exhaust pipe to be thermally expanded in the longitudinal direction, and an amount of thermal expansion of the exhaust pipe and an amount of thermal expansion of the heat insulator differ from each other, it is unlikely that stress is generated in the heat insulator because the other end side of the heat insulator does not follow thermal expansion of the exhaust pipe.